This invention relates to improving the characteristics of arylene sulfide polymer compositions.
It is known that arylene sulfide polymers are useful in coating applications. Coatings formed thereof are strong, heat stable and resistant to most industrial chemicals and fumes. Thus, for example, arylene sulfide polymers can be advantageously employed as coating for metals such as steel, aluminum, nickel, brass, copper, as well as ceramics, glass and other substrates stable at the curing temperature required for the coating which can run as high as 800.degree. F. (427.degree. C.).
Arylene sulfide polymer is also ideally suited for other molding techniques such as extrusion and injection molding. However, in many instances the polymer as produced, while having a very high melting point, nonetheless has an extremely low melt viscosity with the melt flow number (MFN) as measured by ASTM D 1238-65T (modified to use a 5 kilogram weight and a temperature of 288.degree. C.) being greater than 2500 g in 10 minutes. To be usable in most applications, a melt flow in the range of only 1-200 is generally required.
It is known that the cure rate can be increased to some extent through the use of various additives as shown for instance by Blackwell U.S. Pat. No. 3,879,355. However, even with such accelerators, a substantial time at an elevated temperature is required to effect significant changes in the melt flow characteristics. Some materials which might be thought of as crosslinking agents have little or no effect on arylene sulfide polymers and may even cause an increase in melt flow. Thus, it would be desirable to find a promoter to cut the time and/or temperature required, and at the same time be usable at low levels so as to avoid side effects on other properties of the polymers.